The stability of L3 sponge phase in acidic solutions

In the synthesis of the disordered lyotropic liquid crystalline L3 sponge phase prepared with the cosurfactants cetylpyridinium chloride and hexanol, aqueous NaCl solution is used as the solvent. When this sponge phase is used as the template for L3 silica-phase processing, we replace NaCl with HCl to facilitate the acid catalysis of tetramethoxysilane in forming a templated silica gel, assuming that changing the solvent from NaCl(aq) to HCl(aq) of equivalent ionic strength does not affect the stability range of the L3 phase. In this work, we confirm that changing the pH of the solvent from neutral to acidic (with HCl) has negligible effect on the L3 phase region. Equivalent ionic strength is provided by either NaCl(aq) or HCl(aq) solvent; therefore, a similar phase behavior is observed regardless of which aqueous solvent is used.     

Mazur's Principle for Totally Real Fields of Odd Degree

In this paper, we prove an analogue of the result known as Mazur's Principle concerning optimal levels of mod Galois representations. The paper is divided into two parts. We begin with the study (following Katz–Mazur) of the integral model for certain Shimura curves and the structure of the special fibre. It is this study which allows us to generalise, in the second part of this paper, Mazur's result to totally real fields of odd degree.     

Construction of Euclidian Monopoles

This paper describes a procedure for the construction of monopoleson three-dimensional Euclidean space, starting from their rationalmaps. A companion paper, ‘Euclidean monopoles and rationalmaps’, to appear in the same journal, describes the assignmentto a monopole of a rational map, from CP¹ to a suitable flagmanifold. In describing the reverse direction, this paper completesthe proof of the main theorem therein. A construction of monopoles from solutions to Nahm's equations(a system of ordinary differential equations) has been well-knownfor certain gauge groups for some time. These solutions arehard to construct however, and the equations themselves becomeincreasingly unwieldy when the gauge group is not SU(2). Here, in contrast, a rational map is the only initial data.But whereas one can be reasonably explicit in moving from Nahmdata to a monopole, here the monopole is only obtained fromthe rational map after solving a partial differential equation. A non-linear flow equation, essentially just the path of steepestdescent down the Yang-Mills-Higgs functional, is set up. Itis shown that, starting from an ‘approximate monopole’- constructed explicitly from the rational map - a solutionto the flow must exist, and converge to an exact monopole havingthe desired rational map. 1991 Mathematics Subject Classification:53C07, 53C80, 58D27, 58E15, 58G11.     

Efficient discrimination of transplutonium actinides by in vivo models

Transplutonium actinides are among the heaviest elements whose macroscale chemical properties can be experimentally tested. Being scarce and hazardous, their chemistry is rather unexplored, and they have traditionally been considered a rather homogeneous group, with most of their characteristics extrapolated from lanthanide surrogates. Newly emerged applications for these elements, combined with their persistent presence in nuclear waste, however, call for a better understanding of their behavior in complex living systems. In this work, we explored the biodistribution and excretion profiles of four transplutonium actinides (²⁴⁸Cm, ²⁴⁹Bk, ²⁴⁹Cf and ²⁵³Es) in a small animal model, and evaluated their in vivo sequestration and decorporation by two therapeutic chelators, diethylenetriamine pentaacetic acid and 3,4,3-LI(1,2-HOPO). Notably, the organ deposition patterns of those transplutonium actinides were element-dependent, particularly in the liver and skeleton, where lower atomic number radionuclides showed up to 7-fold larger liver/skeleton accumulation ratios. Nevertheless, the metal content in multiple organs was significantly decreased for all tested actinides, particularly in the liver, after administering the therapeutic agent 3,4,3-LI(1,2-HOPO) post-contamination. Lastly, the systematic comparison of the radionuclide biodistributions showed discernibly element-dependent organ depositions, which may provide insights into design rules for new bio-inspired chelating systems with high sequestration and separation performance.

Transplutonium actinides are among the heaviest elements whose macroscale chemical properties can be experimentally tested.     

Reduction of TiO2 with Hydrogen Plasma

Experiments were performed in a thermal plasma furnace to examine the reduction of TiO₂ by hydrogen plasma. The plasma gas composition was 50% hydrogen–50% argon, the plasma torch input power was 13 kW, the TiO₂ initial mass was 10 g and the processing time was varied from 10 to 90 min. The reaction product contained between 67% and 73% titanium by mass for all tests. This level of reduction was consistent with chemical equilibrium modeling. There was no detectable enhancement of reduction due to the presence of atomic hydrogen. The Ti-O microstructures produced were characterized using quantitative SEM analysis. The microstructures showed a number of similarities with structures described by previous researchers.     

Frequency modulation detection atomic force microscopy in the liquid environment

True atomic resolution imaging using frequency modulation detection is already well established in ultra-high vacuum. In this paper we demonstrate that it also has great potential in the liquid environment. Using a combination of magnetic activation and high-aspect-ratio carbon nanotube probes, we show that imaging can be readily combined with point spectroscopy, revealing both the tip-sample interaction and the structure of the intermediate liquid.     

Generalized Slavnov-Taylor,BRST and covariance identities from the geometry of the gauge surface

It is shown that various Green function identities in quantized gauge theories may be viewed as arising from the local conformal groupSO(N+1, 1) of motions of theN-dimensional gauge fixing surface. Translations and rotations correspond respectively to the usual Slavnov-Taylorinvariance and anew ‘dual’ analogue. Dilations give rise to thecovariance identities, and in axial type gauges we obtain a closed form for the covariance relationships. It is shown that the generalized Slavnov-Taylor identities, and the BRST identities, are equivalent, as are their duals.     

A new look at the crystallization of polyethylene. III. Crystallization from the melt at high supercoolings

Polyethylene melts normally cannot be crystallized in an isothermally controlled manner below ca. 110°C as crystallization is too fast owing to the presence of preexisting nuclei. We here present a new simple method for producing droplets enabling crystallization to be conducted isothermally down to 75°C and allowing measurements to be performed on them, together with the results of these measurements. We conclude that in contrast to the earlier claims the homogeneous nucleation regime has not been attained even at these low temperatures, the crystal nucleation being dominated by the polymer-substrate interface. The droplets crystallized at these low temperatures have a lamellar morphology as revealed by electron microscopy and grow at rates exceeding 1 m s^?1 [i.e., six orders of magnitude faster than growth at more usual crystallization temperatures previously considered as “low” (110–120°C)]. We have measured the lamellar thickness l as a function of growth temperature, thus extending the fundamentally important l vs. ΔT (supercooling) relation beyond the previously realizable limits towards high ΔT values. The implications of all these results for the existing ideas of polymer crystallization are likely to be far reaching. Further, the new method for achieving high supercoolings opens up new possibilities for the study of annealing phenomena and the effect of nucleating agents.